Mineral concentrator



Sept. 13, 1960 I A. A. JOHNSTON 2,952,362

7 MINERAL CONCENTRATOR Filed Jan. 31,. 1958 2 Sheets-Sheet 1' Q 48 INVENTOR.

ISIfl-E-l ARTHUR A. JOHNSTON 4"" 'm' 5 BY ATTORNEY Sept. 13, 1960 Filed Jan. 51, 1958 A. A. JOHNSTON MINERAL CONCENTRATOR 2 Sheets-Sheet 2 ATTQRN EY United States Patent MINERAL CONCENTRATOR Arthur A. Johnston, 711 SE. 11th St., Portland, Oreg.

Filed Jan. 31, 1958, Ser. No. 712,532

Claims. Cl. 209-480) The present invention relates to devices for separating out particles of desired mineral from a mass of miscellaneous particles, such as sand, gravel, and crushed ore, and more specifically, relates to means for separating out and collecting concentrates of a desired heavier mineral, for example, gold, from the rest of the material as it passes through the device.

An object of the invention is to provide an improved impact concentrator in which a high degree of concentration of the desired heavier particles can be satisfactorily.

and efliciently obtained.

Another object of the invention is to provide an impact concentrator in which the degree or richness of the con centration can be controlled and can be varied to suit special conditions.

A further object of this invention is to provide a concentrator which will operate effectively and efficiently under high capacity while requiring a relatively small amount of space in which to operate.

Other objects and advantages will be disclosed in the course of the following brief description in which ref erence is made to the accompanying drawings.

In the drawings:

*Fig. 1 is a sectional elevation of the device taken on the line indicated at 1--1 in Fig. 4;

Fig. 2 is a fragmentary side elevation taken on line 22 of Fig. 1 but drawn to a slightly smaller scale;

Fig. 3 is a fragmentary enlarged view of one of the pairs of adjustable directing and dividing fins or splitters which are provided in each of the compartments in the superimposed launders of the device;

Fig. 4 is a top plan view of line 4-4- of Fig. l, but with portions of the receiving and distributing hopper and the underlying top wall of one of the launders broken for clarity; and

'Fig. 5 is a fragmentary elevation of a lower portion of a device showing a simple adjustable vibrating or oscillating means for the device.

Referring first to Figs. 1, 2 and 4, the device includes a rigid main supporting framework assembly having a substantially rectangular base 10, a pair of vertical A- frames 11 and 12 extending upwardly from each end of the base, anda horizontal top channel member 13 rigidly connecting the upper ends of the two A-frames.

An integral oscillatable frame 1 4, composed preferably of channel irons formed into a hollow rectangle, has a bottom central mounting consisting of an inverted disc 15 having a concave bottom face which is rotatably sup ported on a stationary mounting member 16, which in turn is secured to the base 10 and which has a corresponding convex top surface. At the center of the top of the frame 14 a rotatable bearing assembly 17 connects this frame 14 to a stationary mounting member 13 which is secured to the top channel member 13 of the stationary support frame.

A distributing hopper, designated as a whole by the reference character 18, is mounted in the top portion of the oscillatable frame 14, being attached to the frame sides by ears (one of which is shown at 19 in Fig. 2) secured by suitable screws. The hopper 18 has a pair of downwardly and inwardly sloping bottom walls 20 and 21 (Fig. 1), a pair of vertical top side walls 22 and 23, and vertical end walls 24 and 25. The end walls 24 and 25 (see Fig. 4) preferably comprise central portions 24 and 25 respectively, extending in vertical planes parallel to the side members of the frame 14, while the main portions of each end wall extend in parallel vertical planes which however are arranged at an angularity with respect to the central portions 24' and 25'. These end walls correspond to the end walls of a lower housing as explained later. The mineral in particle form, from which the desired concentrates are to be separated, is delivered into the hopper 18.

The bottom walls 20 and 21 of the hopper 18 terminate in the central portion along the bottom and give place to a series of staggered outlets through which the material in the hopper is distributed to a double series of superimposed launders or separator pans mounted below the two bottom walls of the hopper. In the particular device illustrated there are five launders on each side, each launder consisting of a pan in the shape of a parallelogram having a downwardly-outwardly sloping bottom wall. Thus, referring to Fig. 1, the launders in the series located on the left are indicated at 26, 27, 28, 29 and 30, reading from top to bottom, and the: corresponding launders in the other series on the right are indicated at 26', 27, 28', 29' and 30.

A series of spaced vertical partitions, located below the central bottom portion of the hopper 18 and having their top ends terminating a short distance below the hopper, as shown in Fig. I, extend from one end wall of a housing 37 to the other and lead downwardly until they meet the inner upper ends of the bottom walls of the respective launders. Thus in Figs. 1 and 4 these vertical partitions are shown at 26A, 27A, 28A and 29A for one series of launders, and 26A, 27A, 28A, and 29A for the other series of launders. A central passageway 30A, between the two inner partitions 22A and 29'A leads to the lowest launders 3t 30, as shown in Fig. 1, and the bottom walls of these two lowest launders meet at the center line so that the material passing down through the passageway 30A will be divided between the two bottom launders.

From Figs. 1 and 4 it will be apparent that, if the vertical partitions 26A 29A and 26'A 29'A were the only means for controlling passage of the material from the hopper to the various launders, more material would be discharged into some launders than into others. In order to make distribution of material more nearly equal, groups of distributor troughs are provided in the central bottom portion of the hopper 18 spaced above the vertical partitions as shown in Fig.

1. Thus the distributor troughs 31 and 31 lead from,

opposite sides on the bottom of the hopper and terminate above the central passageway 30A so that most of the. material reaching these distributor troughs will be directed down to the two launders 30 and 30 instead of being delivered into any of the other launders. Similarly, most of the material reaching the troughs 32 and 32' will be delivered intothe launders 29 and 29 respectively; material reaching the troughs 33 and 33 will be delivered mainly into the launders 28 and 28' respectively; material reaching the troughs 34 and 34 will be .de: livered largely into launders 27 and 27 respectively; while most of the materialwhichavoids these distributor troughs will pass down into the two top launders 26 and are placed in any suitable arrangement along the hopper so .asto provide a fairly even distribution of material from the hopper among the various launders.

The sloping bottom walls of the launders or separator pans extend between and are supported by a pair of end walls 35 and36 (Fig. '1) of a closed housing indicatedin general by the reference character 37. This housing is supported in the oscillatable frame '14 below the hopper 18 (see Fig. 2), and is secured to the frame 14 in the same manner 'as 'the hopper 18. The end walls 35 and 36 of the launder housing 37 are vertical, and the portions of the end walls of the housing 37 are located in the same vertical planes as the corresponding portions of the end walls of the hopper respectively. The housing 37 has a sloping bottom wall 38 (Fig. '1), side walls 39 and 40, and top walls 41 and 4-2 which are parallel to the bottom walls of the respective series of launders, and the top walls are integrally joined with the bottom walls and 2.1 respectively of the hopper 18.

Each launder is divided into a series of compartments of equal width by partitions which extend from the top to the bottom of the launder and which are parallel to the end walls 35 and 36 of the housing 37. These partitions, shown for the top launder 26 in Fig. 4, are indicated by the reference character 43. These parallel vertical partitions extend downwardly obliquely to the side walls 39 and 40 of the housing 37. Thus each of the compartments in each launder has one side wall forming an obtuse angle with the side wall of the housing to which it extends and an opposite wall forming an acute or supplementary angle with such side wall of the housing in the compartment. The portions of the end walls 35 and 36 of the housing 37 extend in the vertical planes previously described in-order to be parallel to the partitions 43 and enable all the compartments of the launders to be of the same shape and size. The bottom walls of the individual launders or separator pans do not extend entirely to the side walls 39 and 40 of the housing 37. The partitions 43, however, do extend to the housing side walls and the corresponding partitions of the superimposed launders merge adjacent the side walls of the housing, so as to form sides for vertical passageways 44 (Fig. 4), located beyond the launders, and extending downwardly therefrom and terminating near the bottom of the housing 37. The passageways 44 are completed by the additional downwardly-extending Walls 45. Companion downwardlyextending passageways 46 (Fig. 4), adjacent the passageways 44 respectively, are provided by additional vertical walls 47. Thus each compartment in each launder terminates or discharges in part into the two downwardlyextending passageways or channels 44 and 46 leaving the rest of the material in the compartment to be discharged down through a remaining passageway or channel 48.

The housing 37 is provided with an outside pair of superimposed closed chambers 49 and 50 (Fig. 1), located adjacent the bottom of the housing and extending the entire length of the housing on each side (see also Fig. 2.). The arrangement is such that the downwardly-extending passageways 44 discharge into the lower chamber 50 on the respective sides of the housing 37. Similarly the adjacent downwardly-extending passageways 46 discharge into the chambers 49. The two pairs of chambers 49 and 50 are provided with discharge outlets 51 and 52 respective y.

As previously mentioned, there is a third downwardlyextending passageway 48 leading from each compartment of each launder. These passageways 48 discharge into the bottom of the housing 37 and thus discharge onto the sloping bottom wall 38 (Fig. 1) within the housing 37. A discharge outlet 53 extends along the housing 37 at the lower end of the bottom wall 38, and thus material from the launders which does not reach either of the chambers 49 or 50 will be discharged from the outlet 53.

The frame 14, and with it the hopper 18, housing 37, and the various launders, receive rapid oscillating impulses or impacts by .means of a pitman 54 (Figs. 4 and 5) mounted on a rotating driven flywheel disc 55. The pitman 54 "extends slidably through an aperture in -a bracket arm 56 secured to one side of the frame 14. A nut 57 and an interposed cushioning washer 58 are mounted on one end of the pitman 54 beyond one side of the arm 56. A coil spring 59 on the pitman engages the other side of the arm 56 and is held under compression between the arm 56 and an :adjustable nut 60 on the pitman.

It will be noted from Figs. 4 and'5 that rotation of the flywheel disc 55, for example, in counter-clockwise direction, will cause the frame 14 and with it the housing 37, to oscillate on a vertical axis. In such oscillation each thrust given to the arm -56 of the frame 14 towards the left (Figs. 4 and 5) will be cushioned by the coil spring 59, but the pull on the arm 56 by the pitman 54 in the opposite direction, or towards the right, will not be so cushioned. In other words, in the oscillation imparted to the housing 37, the shock received with each oscillation impulse, causing the housing to swing in counter-clockwise direction (as viewed in Fig. 4), will be more severe than the shock imparted during the opposite oscillation impulse. When the housing receives the impulse causing it to move counter-clockwise, the particles of material, which are sliding down in the launder compartments towards the 'lower or discharging ends of 'the bottom walls of the compartments, in reacting to such impulse, will have a tendency to be moved closer to that side partition'or Wall in each compartment which forms the obtuse angle in the compartment with the side wall of the housing. The impetus received by the housing with the opposite oscillation impulse will tend to produce an opposite effect on the moving particles of material, which opposite efiect, however, due to the slightly cushioned impulse, will be less pronounced particularly in the case of the particles having the greatest density or weight, since their momentum will .be less influenced by the lighter impulses. Thus, as the particles of material slide down in the compartments and react to the rapid succession of oscillation impulses received by the entire housing assembly, the heavier particles will show a more constant tendency to approach closerto the compartment wall which forms theobtuse angle in the compartment, and consequently a considerable portion of these heavier particles in each compartment will finally be discharged down the passageway 44 leading from the compartment. A considerable portion of the less heavy particles on the other hand will react also to the minor oscillation impulses and consequently not .have their courses directed as closely towards the same wall, and such portion, commonly referred to as middlings, will to a large extent he therefore discharged .downthe passageway 46 from each compartment. Finally the lighter weight particles, commonly referred to as tailings, reacting under both oscillation impulses, will, :to considerable extent, find their way down to the third and larger discharge passageway 48 from each compartment.

As previously explained, that portion of the heavier particles of material (with most of the desired concentrates), which passes down the passageways 44, will then be discharged from the outlets 52 of the chambers :50; the middlings, passing down the passageways 46, will be discharged from the outlets 51 of the chambers 49; and the tailings or remainder of material will be discharged from the outlet '53 at the bottom of the housing '37.

The arrangement thus far described provides for a good general average concentration of the desired heavier particles and for the dividing or splitting of the material in the process into the three general classes of concentrates, middlings, and tailings. However, ithas been found that with the use of additional adjustable dividing and directing vanes or splitters in the launders of this device, important variations and richer concenass-te se trations can be obtained when desired and conditions justify. For this purpose an adjustable directing vane or splitter '61 (see Figs. 1, 4 and 5) is mounted in each compartment of each launder ahead of the vertical, downwardly-extending side wall 45. The corresponding vanes 61 in the corresponding compartments of the superimposed launders in each of the two series of launders are attached to a common vertical shaft 63. These vertical shafts 63 are rotatably mounted in the device and an adjusting finger 65 is secured to the top of each shaft 63 above the top Wall of the housing 37.

The manner in which each vane or splitter 61 is secured to its control shaft is illustrated in Fig. 3. A sleeve 67 is secured on the control shaft 63 by a set screw 68. The sleeve 67 is provided with a pair of ears 69 between which the vane 61 is inserted, and a pin 70, extending between the pair of ears and passing through a suitable aperture in the vane 61, provides a pivotable support for the vane 61 and thus allows the vane to rest on the bottom wall of the compartment and to be swung to a desired limited extent in either direction when the shaft 63 is given partial rotation.

A second series of vanes or splitters 62 is similarly positioned in each of the corresponding compartments of the superimposed launders ahead of the vertical downwardly-extending walls 47, and these second series of vanes 62 are similarly mounted on vertical shafts 64 which terminate above the top of the housing 37 and which similarly carry adjusting fingers 66 (see Fig. 4). Indicator scales 71 on the top of housing 37 for these adjusting fingers 65 and 66 enable all the vanes of splitters in the device to be set to any adjusted position desired.

The alfect of adjustments in the positions of the vanes or splitters 61 and 62 in each compartment of each of the launders will be apparent with reference to Fig. 4. When the vanes 61 are moved slightly counter-clockwise (as viewed in Fig. 4) from their starting position in alignment with a downwardly-extending wall 45, they reduce the size of the entrance into the downwardly-extending channels 44 and restrict the material which moves down into these passageways to the heavier particles or concentrates which will be moving closer to the adjacent compartment wall or partition as a result of the oscillating impact imparted to the device. In other words, by moving the vanes 61 so that they reduce the size of the entrance into the passageways 44, the richness in desired concentrates of the portion of the material caused to pass down the passageways 44 (and thus be delivered from the outlets 52 of the device) will be increased. Furthermore, for example, the moving of the vanes 62 also, but in clockwise direction (as viewed in Fig. 4), will not only increase the proportionate amount of material from the compartments which will be delivered into the downwardly-extending passageways 44, 46, but will reduce the amount of desired particles which might escape into the remaining broader downwardly-extending passageways 48. Consequently the second vanes 62 in each compartment can be used for making the tailings more barren and making the middlings richer. This is important, especially when the middlings are going to be given further treatment or put through the device a second time and also when the material is of such nature that there is an opportunity of collecting other minerals by reprocessing the middlings.

Thus this improved concentrator not only enables the material to be distributed from the hopper simultaneously to a number of pans or launders, with the material in each pan or launder distributed throughout a number of compartments, with the desired separation and concentration occuning in each compartment and, with the separated classifications or grades of material collected from the bottom ends of these compartments, but, with the addition of the adjustable vanes of splitters, the device also enables variations in the relative richness of the classifications to be made whenever conditions make this desirable.

I claim:

1. In a mineral concentrator of the character described, a housing, a pan in said housing, said pan having a bot tom wall sloping downwardly to one side of said housing, a plurality of parallel equally-spaced partition side walls extending downwardly in said pan to the lower edge of said bottom wall and dividing said pan into identical, downwardly-sloping compartments, means including hopper for delivering mineral particles into the upper ends of said compartments, means for imparting oscillating partial rotation to said housing and pan on a substantially vertical axis, said oscillating means so arranged as to produce more forceful impacts in one direction than in the opposite direction, said more forceful impacts tend: ing to direct the mineral particles towards one side wall in each compartment and the opposite oscillation impacts tending to direct the mineral particles towards the opposite side wall in each compartment, but the weaker oscillation impacts exerting relatively less influence on the heavier mineral particles in comparison with that exerted by the more forceful impacts than in the case of the lighter mineral particles due to the momentum of the heavier mineral particles under the more forceful impacts, whereby the heavier mineral particles will be relatively closer to one side wall in each compartment as the mineral particles reach the lower ends of said compartments, a plurality of passageways adjacent each other leading from the lower end of each compartment and means for separately collecting the mineral particles from corresponding passageways leading from said compartments.

2.. In a mineral concentrator of the character described, a housing, a pan in said housing, said pan having a bottom wall sloping downwardly to one side of said housing, a plurality of parallel equally-spaced side partition walls extending downwardly in said pan to the lower edge of said bottom wall and dividing said pan into identical downwardly-sloping compartments, one of said side partition walls in each compartment forming an obtuse angle with said housing side and with the lower edge of said bottom wall of said pan in the compartment, means including a hopper for delivering mineral particles into the upper ends of said compartments, means for imparting oscillating partial rotation to said housing and pan on a substantially vertical axis, said oscillating means so arranged as to produce more forceful impacts in one direction than in the opposite direction, said .more forceful impacts tending to direct the mineral particles towards one side partition wall in each compartment and the opposite oscillation impacts tending to direct the mineral particles towards the opposite side in each compartment but the weaker oscillation impacts exerting relatively less influence on the heavier mineral particles in comparison with that exerted by the more forceful impacts than in the case of the lighter mineral particles due to the momentum of the heavier mineral particles under the more forceful impacts, whereby the heavier mineral particles will be relatively closer to one side in each compartment as the mineral particles reach the lower ends of said compartments, a plurality of passageways adjacent each other leading from the lower end of each compartment, means for separately collecting the material from corresponding passageways leading from said compartments, hinged vanes in each compartment at the entrance to said passageways and means for adjusting said vanes so as to modify the directing of material into the respective passageways when desired.

3. In a mineral concentrator of the character described, a housing, a group of superimposed identical pans in said housing, each pan having a bottom wall sloping downwardly to one side of said housing, said bottom walls of said pans extending in parallel planes, a plurality of parallel equally-spaced side partition walls extending downwardly in each pan to the lower edge of the bottom wall of each pan and dividing each pan into downwardlysloping compartments, the compartments in all of said pans being identical, a hopper on said housing, said hopper having a series of bottom outlets connected with said pans respectively for delivering mineral particles into the upper ends of said compartments in said pans, means for imparting oscillating partial rotation to said housing on a substantially vertical axis, said oscillating means so arranged as to produce more forceful impacts in one direction than in the opposite direction, said more forceful impacts tending to direct the mineral particles towards one side partition wall in each compartment and the opposite oscillation impacts tending to direct the mineral particles towards the opposite side partition wall in each compartment but the weaker oscillation impacts exerting relatively less influence on the heavier mineral particles in comparison with that exerted by the more forceful impacts than in the case of the lighter mineral particles due to the momentum of the heavier mineral particles under the more forceful impacts, whereby the heavier mineral particles will be relatively closer to one side wall in each compartment of each pan as the mineral particles reach the lower ends of said pans, a plurality of passageways adjacent each other leading from the lower end of each compartment of each pan, and means for separately collecting the mineral particles from corresponding passageways leading from said compartments of each pan.

4. In a mineral concentrator of the character described, a housing, two groups of superimposed identical pans in said housing, the pans in one group having bottom walls sloping downwardly to one side of said housing in parallel planes, the pans in the other group having bottom walls sloping similarly downwardly to the opposite side of said housing in parallel planes, a plurality of parallel equallyspaced partition walls extending downwardly in each pan to the edge of the bottom wall of each pan and dividing each pan into downwardly-sloping compartments, the compartments in all of said pans being identical, a hopper on said housing, said hopper having a pair of downwardly and inwardly sloping bottom walls, a series of staggered outlets located along the center of the bottom of said hopper and connected with said pans respectively for delivering mineral particles into the upper ends of the compartments in each of said pans, means for imparting oscillating partial rotation to said housing on a substantially vertical axis, said oscillating means so arranged as to produce more forceful impacts in one direction than in the opposite direction, said more forceful impacts tending to direct the mineral particles towards one partition wall in each compartment and the opposite oscillation impacts tending to direct the mineral particles towards the opposite partition wall in each compartment but the weaker oscillation impacts exerting relatively less influence on the heavier mineral particles in comparison with that exerted by the more forceful impacts than in the case of the lighter mineral particles due to the momentum of the heavier mineral particles under the more forceful impacts, whereby the heavier mineral particles will be relatively closer to one partition wall in each compartment in each of said pans as said mineral particles reach the lower ends of said pans, a plurality of passageways adjacent each other leading from the lower end of each compartment of each pan, and means for separately collecting the mineral particles from corresponding passageways leading from said compartments and pans.

5. In a mineral concentrator of the character described, a housing, two groups of superimposed identical pans in said housing, the pans of one group having bottom walls sloping downwardly to one side of said housing in parallel planes, the pans in the other group having bottom walls sloping similarly downwardly to the opposite side of said housing in parallel planes, a plurality of parallel equallyspaced partition walls extending downwardly in each pan to the edge of the bottom wall of each pan and dividing each pan into downwardly-sloping compartments, the compartments in all of said pans being identical and the corresponding partition Walls in the pans of each group being in vertical alignment, one of said partition walls in each compartment in each group of pans forming an obtuse angle with the housing side adjacent the lower end of such partition wall in each compartment, a hopper on said housing, said hopper having a pair of downwardly and inwardly sloping bottom walls, a series of staggered outlets located along the center of the bottom of said hopper and connected with said pans respectively for delivering mineral particles into the upper ends of the compartments in each of said pans, means for imparting oscillating partial rotation to said housing on a substantially vertical axis, said oscillating means so arranged as to produce more forceful impacts in one direction than in the opposite direction, said more forceful impacts tending to direct the mineral particles towards one partition wall in each compartment and the opposite oscillation impacts tending to direct the mineral particles towards the opposite partition wall in each compartment but the weaker oscillation impacts exerting relatively less influence on the heavier mineral particles in comparison with that exerted by the more forceful impacts than in the case of the lighter mineral particles due to the momentum of the heavier mineral particles under the more forceful impacts, whereby the heavier mineral particles will be relatively closer to one partition wall in each compartment in each of said pans as the mineral particles reach the lower ends of said pans, a plurality of passageways adjacent each other leading from the lower end of each compartment of each pan, means for separately collecting the material from corresponding passageways leading from said compartments and pans, hinged vanes in each compartment at the entrance to said passageways, whereby said vanes may be employed to modify the directing of material into the respective passageways when desired, the corresponding vanes in the corresponding compartments of each group of pans being attached to a common adjusting shaft, and adjusting elements at the top of said shafts, whereby the corresponding vanes in each group of pans can be adjusted uniformly.

References Cited in the file of this patent UNITED STATES PATENTS 258,879 Blatchly June 6, 1882 2,087,092 Lynch July 13, 1937 2,263,143 Record Nov. 18, 1941 2,577,565 Bradley Dec. 4, 19-51 2,822,090 Johnston Feb. 4, 1958 PAW) 

